A 2-(1-alkylaminoalkyl)-3-hydroxy-1,4-naphthoquinone of the formula: ##STR1## wherein R.sup.1 is an alkyl group or a cycloalkyl group, and R.sup.2 is an alkyl group having at least 2 carbon atoms. The compounds are used in the preparation of a 2-(1-alkenyl)-3-hydroxy-1,4-naphthoquinone having insecticidal and fungicidal activity and a 2-alkyl-3-acyloxy-1,4-naphthoquinone having insecticidal and fungicidal activity and a 2-alkyl-3-acyloxy-1,4-naphthoquinone having miticidal activity.
2-(1-alkylaminoalkyl)-3-hydroxy-1,4-naphthoquinone, process for its production and processes for producing 2-(1-alkenyl)-3-hydroxy-1,4-naphthoquinone and 2-alkyl-3-acyloxy-1,4-naphthoquinone by using it